Centrifugal pump.



F. W. & 0. A. KROGH.

GENTRIFUGAL PUMP.

APPLICATION FILED APR.5,1904.

Patented 0011.4, 1910.

5 SHEETS-SHEET 1.

' wmw I. W. & 0. A. KROGH. GENTRIFUGAL PUMP. APPLICATION FILED APE. 5,1904.

Patented Oct. 4, 1910.

5 SHEETS-SHEET 2.

zimg E I 1 T @515 I I a 9 i 5? F. W. (Yr, 0. A. KROGH.

CENTRIFUGAL PUMP.

Patented 0013. 4,1910.

5 SHEETS-SHEET a.

F. W. 85 G. A. KROGH.

CENTRIFUGAL PUMP.

APPLICATION FILED APE. 5,,1904.

Patented 0011.4,1910.

5 SHEETS-SHEET 4.

F. W. & G. A. KROGH.

GENTRIFUGAL PUMP.

Patented Oct. 4, 1910.

5 SHEETSSHBET 5.

QZZ/LEE APPLICATION FILED APR 5 1904 UNITED %TATE% PATENT @FFIQ.

FERDINAND W. KROGI-I AND CARL A. KROGH, OF SAN FRANCISCO, CALIFORNIA.

CENTRIFUGAL PUMP.

Specification of Letters Patent.

Patented Get. a. rare.

Application filed April 5, 1904. Serial No. 201,719.

To all whom it may concern: I

Be it known that we, FERDINAND W. Knooir and CARL A. KRocH, citizens of the United States, residing at San Francisco, in the county of San Francisco and State of California, have invented certain new and useful Improvements in Centrifugal Pumps, of which the following is a specification.

()ur invention relates more particularly to centrifugal pumps mounted either vertically or horizontally as the case may be, and its principal object is to provide that class of machinery with improved means for preventing leakage of water between the stationary and moving parts whilein operation.

To this end the invention consists in certain peculiarities in the construction and arrangement of parts and in certain novel combinations of elements substantially as hereinafter described and particularly pointed out in the subjoined claims.

In the annexed drawings illustrating the invention: Figure 1 represents a central vertical section of a vertical centrifugal pump showing our adjustable packing-ring in position between the stationary and moving parts and the means by which same is adjusted and held in place; Fig. 2 represents. a fragmentary central section of a horizontal centrifugal pump showing our improvements in place thereon; Fig. 3 is a vertical cross section taken from dotted line 1 to l of Fig. 2 looking in the direction of the arrows; Fig. 4 is a vertical cross section taken from dotted line 2 to 2 of Fig. 2 looking in the direction of the arrows and Figs. 5, (i, 7 and 8 are fragmentary sectional views showing various modifications of our improvements.

Like letters of reference made use of in the several figures indicate like parts wherever employed.

Referring first to the form shown in Fig. 1, A represents the casing or stationary part; B the impeller mounted vertically in the casing and provided with the neck a and downwardly projecting hub b; C the suction pipe or water inlet secured to the casing; D balancing cylinder mounted centrally upon the suction pipe; and E the driving shaft for the impeller, extending through the casing and balancing cylinder and supported by bearings c, d, e. Said shaft opcrates a balancing means which comprises a piston F fixed to the driving shaft within the balancing cylinder, liquid chambers f, f

above and below the piston to balance the same, valved pipes g, g connected to the liquid chambers and t0 the supply pipe G and a lever I'I secured to the driving shaft above the balancing cylinder and connected to the valves 71., b, of said pipes to automatically control the passage of liquid to said chambers.

The balancing means above set forth being made the subject matter of another application for Letters Patent filed byus Nov. 27, 1903, (Serial No. 182,870) is not claimed herein.

The parts above described are comprised in a construction of vertical centrifugal pump selected to exemplify the present invention with said type of pump. Our invention however, (as shown in Fig. 2, in which A represents the casing, B the impeller and C the suction inlets, and as further shown in Fig. 5 in which the casing, impeller and suction inlets are designated by the characters A 2 and C respec tively) is equally applicable to a pump having a horizontally-arranged impeller as it is particularly intended to provide means between the meeting portions of the impeller and the casing and betweenthe piston F and the inner projecting annular flange I of the balancing cylinder for the purpose of preventing leakage betwecn these various parts. Thus in the joints of the parts above described there are provided adjustable packing-rings (lettered J in Fig. 1, J in Figs. 2 and 4c and J in Fig. 6) of suitable material having in preference a right angle or l. shaped appearance in cross section as shown in the drawings. These rings thus provide inner cylindrical bearing faces which engage annular collars or sleeves 2', z, 2', 2' 2* or i (hereinafter described) secured to the moving parts, and bearing faces at right angles with said cylindrical bearing faces to engage the stationary part of the machine.

As shown in Figs. 2 and 5 the'stationary part may have recesses I: to receive the portion of the ring engaged with said stationary part, but said recesses may be dispensed with in some cases, if desired. v

In practice the packing-rings are secured against the stationary parts by means of suction created by the rotating movements of the impeller, which communicates with the packing-rings through openings or spaces arranged to provide vacuum chambers formed annularly within the casing and having communication with the suction inlets or pipes C or O or C and with said rings. Provision for free communication to the rings of suctional force adequate for the purpose may be variously made without departing from the spirit of the invention and several such are shown, as examples, in the accompanying drawings. Thus, in Fig. 1, the vacuum chamber (K) is formed by an annular open space which is contiguous to the neck a of the impeller and leads directly from the suction pipes C to the packingring J, being thereby so arranged as also to provide for the shifting movements of the impeller which occur while in operation.

In the form shown particularly in Figs. 2, 3 and at, the vacuum chamber (K') is located behind the packing ring J and the suction pipes C project inwardly around the inner circumference of the neck a of the impeller and have the circumferences of their inner ends formed with longitudinal grooves 1%, whereby communication with said vacuum chamber is established, and the inner wall of said chamber has passages Z leading from the vacuum chamber to said packing ring. The shifting movements of the impeller in this form are preferably accommodated by a space 0 between and communicating with the vacuum chamber K and grooves m, said space thus practically forming a part of the vacuum chamber. Communication between the vacuum chamber and packing ring and the suction inlet may be otherwise secured without departing from the spirit of the invention or the scope of the subjoined claims. For example, the same result may be secured by omitting the portion of the suction pipe which in Fig. 2 projects beneath the impeller and contains the groove m and by omitting the portion of the wall of the vacuum chamber which contains the passages Z. This form is shown in Fig. 5 in which K designates the vacuum chamber. The hub 79 shown exclusively in Fig. 1 is provided with chambers formed by apertures a leading to chamber L formed below, thus communicating the suction to the packing-ring placed at that portion for the purpose above indicated, attention being called to the fact that the ring and chamber are relatively so disposed that a sufiicient extent of surface of the ring will be presented to the suctional force in the chamber to enable the ring to be held to-its seat thereby. Thus, as shown, the wall of the chamber is so arranged with relation to the axis as to provide a space of definite diameter around the latter, and this space is not filled by the depending member of the packing ring (here shown as extending into said chamber) and that the other member of the ring, which is seated upon the stationary portion of the pump, extends for a considerable portion of its length over said space,

annular bands p made of soft thin material and secured thereto by screws 9 or other suitable means. These bands p are tightly and flexibly seated against the moving and stationary parts of the machine and seal up the edge of the packing-rings while the suction draws the rings firmly in position against the stationary part as already mentioned. In all the forms the stationary parts are shown as provided with means for confining the packin ring (when the machine is out of operation) against movement from their seats to an extent which will place them beyond the sphere of influence of said suction, said confining means comprising suitable devices, such as brackets M consisting preferably of spaced strips (shown best in Fig. 4:) projecting from said stationary parts and overlapping the rectangular portion of the packing-ring in such a manner, however, as to not interfere with its movements while adjusting itself in position. These brackets are secured to the stationary parts by means of screws 1- and retain the packing-rings in position close to the stationary parts when not in operation. The collars previously mentioned constitute seats on the moving parts for the packing rings, which seats are thereby formed separately from said moving parts (the piston F and the impeller) and are removable therefrom. They may be secured in various ways such as are shown for instance in Figs. 1, 2, 5, 6, 7 and 8 as follows: I

In Fig. 1 each collar 2' is of right angle shape in cross section and is secured to the moving part by screws 8 of which the heads only are seen; in Fig. 2 it (designated 2") is secured in position around the neck of the impeller by means of rivets t; in Fig. 5 the neck of the impeller B is cutaway and the collar (2' is provided with an annular outwardly projecting flange N screwed or bolted to the side of the impeller; in Fig. 6 the collar (2' is made of elastic material and forced into a circumferential groove formed for that purpose upon the neck a of the impeller B in Fig. 7 it (designated 6*) is secured in position by means of threads cut inwardly thereon and meshing with correspondin threads formed upon the neck a, of the impeller B and in Fig. 8, it (designated 2' is tongued and grooved to the neck a of the impeller B and secured thereon by means of screws u.

We do not herein claim the means for preventing leakage which are shown, described and claimed in our application filed Septem become Patent No. 815,439 issued March 20, 1906) but Having described the nature and object of our invention and illustrated various examples of its application in practice and believing we have produced novel and valuable improvements in that class of machinery for the purpose of preventing leakage between the stationary and moving parts What we claim as new and desire to secure by Letters Patent of the United States is:

1. In a centrifugal pump, a relatively movable casing and an impeller, the impeller mounted in the casing and so related thereto as to provide a space between its outer portion and the inner Wall of the casing and one of the parts formed to provide a vacuum chamber leading to said space, the casing having a suction inlet in communication with the chamber, in combination with a packing element engaging the casing and impeller and closing communication between the space and the vacuum chamber and held to its seat by the suction in the chamber.

2. A machine of the class described having a suction inlet, relatively movable parts, a packing device at the junction of said parts, sai packing being adapted to be held in packing position by suction from said inlet and said junction having provision for free communication of the packing with the suction inlet, whereby it is exposed to sufiicient suction to be efiectively held thereby, and a supporting device for the packing, so related to said junction that it will confine the packing against movement away from the place where the suction can efiectually hold it.

3. A machine of the class described, comprising relatively movable parts and a packing means between said parts, said machine being formed to provide a vacuum chamber having free communication with the vacuum portion of the machine and the packing means, and through which the packing means is held to its seat by suction when the machine is in operation and having means for confining said packing means, when the machine is not in operation, against movement beyond the sphere of operation of the suction.

4. A machine of the class described, comprising a suction inlet and stationary and moving parts having contiguous portions, a vacuum chamber having free communication with the suction inlet, a packing device ex posed to suction through said chamber and a supporting means for the packing device, so arranged as to confine the latter permanently within the effective area of the suction, said parts so related to each other that.

the packing will be held to its seat by the suction to which it is exposed in the operation of the machine.

5. A machine of the class described,-comprising a stationary and a movin part, a packing ring for preventing lea age between said parts and means for confining the ring against movement beyond predetermined limits from its seat, said machine having means by which when it is in operation t e packing ring is drawn and held to its seat by suction created in the movement of its movable part comprising a vacuum chamber exposed to said suction and to the ring.

6. A machine of the class described, comprising stationary and moving parts and a packing ring seated on the moving part, said stationary part having a vacuum chamber which freely communicates with a suction Dortion of the machine and said packing having sufficient of its area freely exposed to said chamber to cause it to be held to its seat by the suctional force exerted thereon through the chamber.

7. A machine of the class described, comprising stationary and moving parts, said stationary part having a vacuum chamber, apertures leading therefrom and a suction pipe having passages leading to said chamher, and a packing ring mounted on the stationary part contiguous to said apertures and having a bearing face engaging the moving part, said ring having a sufficient area exposed to the suction communicated thereto through the vacuum chamber and apertures to be held to its seat thereby.

8. A centrifugal pump comprising a casing, a suction pipe, an impeller rotatably mounted in the casing, one of said parts l1av ing a vacuum chamber, and a packing between the casing and impeller, said vacuum chamber having communication with the suction portion of the pump and with the packing and said packing having a sufiicicnt area exposed to the suction to be held to its seat thereby, and a device for confining the packing to within the sphere of influence of the suction.

9. A centrifugal pump comprising a casing having a suction pipe, an impeller rotatably mounted in the casing, said casing and impeller having seats adjacent to each other, and a packing ring engaging said seats, said casing having contiguous to its said seat an opening which leads to said ring and through which the ring is exposed to suction and is held by said suction.

10. A centrifugal pump comprising a casing having asuction pipe, an impeller rotatably mounted in the casing, said casing and impeller having seats ad acent to each other, and a packing ring engaging the seats, said casing having contiguous to its said seat a vacuum chamber, and openings through which the vacuum chamber has communication with the suction pipe and the interior of the impeller and with the face of the packing ring, whereby the packing ring is held by the suction created by the movement of said impeller.

11. In the class of machinery described, the combination with the stationary and moving parts, of a packing ring for preventing leakage between the stationary and moving parts, said packing ring having inclined edges, and means secured to the edges to form a water tight joint between said ring and the stationary and moving parts.

12. A machine of the class described, comprising stationary and moving parts, a packing ring arranged between the stationary and moving parts, said packing ring having inclined edges and provided with means to form a water tight joint between the ring and the stationary and moving parts, comprising thin soft bands secured to said inclined edges.

13. A machine of the class described having a suction inlet and relatively movable parts, a packing device at the junction of said parts, and means for confining the packing device against movement appreciably away from said junction, said machine having provision for exposure of the packing device to suction adequate to draw and hold the same to its seat, and said packing device having flexible sealing projection.

14. A centrifugal pump, comprising a casing, an impeller, a packing at the junction of the casing and impeller adapted to be held to its seat by suction, said junction having provision for the exposure of the packing to suction inquantity adequate to hold the packing to its seat and said packing having flexible sealing projecting means, and a supporting device for the packing arranged to confine it within the sphere of influence of the suction.

15. A machine of the class described, comprising a casing and its suction pipe, and an impeller rotatably mounted in the casing, said parts being relatively formed to provide a vacuum chamber ex osed to the suction from said pipe created y the movement of the impeller, and apacking ring arranged between said parts and exposed to suction from the chamber and held to its seat thereby, said ring having a flexible band which is secured to its edge and engages the contiguous part and seals the space at said edge while suction is drawing the packing ring to its seat.

16. A machine of the class described, comprising stationary and moving parts and means for packing the joints between said parts, comprising a ring having its outer edge provided with an inclined flexible band which projects therefrom and is seated against the contiguous part.

17. In a centrifugal pump provided with stationary and moving parts, a packing-ring placed between said stationary and moving parts, in combination with means to retain evaeso the ring within the stationary part, comprising brackets secured to the stationary part and overlapping the ring.

18. A machine of the class described, comprising stationary and moving parts, and a packing means for preventing leakage between the stationary and moving parts, said packing means comprising a ring placed between the stationary and moving parts, and holding means therefor comprising spaced metallic strips secured to the stationary part and adapted to retain the ring.

19. A machine of the class described, comprising a casing and its suction pipe, an impeller rotatably mounted in said casing, a packing ring between the casing and impeller, said machine having one of its parts formed with means whereby the packing ring is held to its seat by the suction created in the movements of the impeller comprising an open chamber exposed to said suction and through which the ring is exposed to the same, and projecting means from one of said parts for confining the packing ring against movement outside the efiective area of the suction.

20. A machine of the class described having its impeller provided with a hub formed with a vacuum chamber which freely communicates with a suction portion of the machine and is thereby exposed to suction created in the movement of the impeller and a packing ring having a suflicient area exposed to suction from said chamber to be effectively held to its seat thereby.

21. A pump of the class described having a casing provided with a chamber, an impeller provided with a hub formed with an aperture through which said chamber has free communication with the suction portion of the pump, and a packing ring interposed between the hub and the casing and having an area freely exposed to the suction communicated thereto through said chamber suificient in extent to cause the packing to be held to its seat by the suction.

22. A pump of the class described having a casing provided with a chamber, an impeller provided with a hub formed with an aperture through which said chamber has free communication with the suction portion of the pump, and a packing ring interposed between the hub and the casing and having an area freely exposed to the suction communicated thereto through said chamber suflicient in area to cause the packing to be held to its seat by the suction and means for confining the packing to within the sphere or" influence or" the suction.

23. In a machine of the class described, a casing, an impeller rotatably mounted in the casing, said casing and impeller relatively formed to provide adjacent to the hub of the impeller a suction chamber and said hub having an aperture through which the chamber is subjected to suction, a packing engaging the impeller and casing and having a bearing face which extends over said chamber a suflicient distance to be held to its seat by the suction in the latter.

24. In a machine of the class described, a casing, an impeller rotatably mounted in the casing, and a packing having a member which is seated upon the casing and is con fined against movementtherefrom, said packing having a-second member which extends around the hub of the impeller and engages a seat which moves with the latter, said casing and hub being relatively formed to provide a chamber between the same, into which the second member of the packing extends, said hub having an aperture through which said chamber is subjected to suction, and the first-member of said ring having a portion of definite length which extends over said chamber a sufficient distance to present to the suctional force therein a face suflicient in extent to be held against its seat by said force.

25. In a centrifugal pump, an impeller provided with a seat having members arranged at an angle with each other, means whereby one of said members is removably secured to the impeller, a casing having a seat, and a packing having faces respectively engaging the latter seat and the other member of the first mentioned seat.

26. In a centrifugal pump, having its neck provided with members arranged at an angle with each other and removably secured t0 the impeller, one of said members forming a seat, a casing having a seat and a packing having faces engaging said seats.

27. In a centrifugal pump, an impeller having a seat which is approximately L- shaped in cross section, securing means whereby said seat may be readily removed from the impeller, a casing having a seat, and a packing engagifn said seats.

In testimony whereof, we have afiixed our signatures in the presence of two witnesses this 1st day of February, 1904.

FERDINAND W. KROGH. CARL A. KROGH. In presence of- E. P. MCMURTRY, GEO; W. ELiAssEN. 

